The L-series is Canon’s flagship professional lens range, designed to include outstanding image performance, ultimate operability and weather resistance. The EF 24-105mm f/4L IS USM offers a lightweight alternative to the renowned EF 24-70mm f/2.8L USM. offers the highest possible optical quality with no change in aperture over the full focal range of the lens. This allows photographers to set exposure at the widest aperture and zoom all the way through to 105mm without having to vary the shutter speed. Image Stabilizer (IS) dramatically reduces image blur caused by camera shake.